There is known a connector sheet with which an electrical connection is made between printed circuit boards or between a printed circuit board and an electronic component, grounding is made between a printed circuit board and a casing of an electronic device having conductivity, or the like. This connector sheet has a configuration in which a conductive portion is provided in an insulating elastic sheet made of a rubber elastic body such that the conductive portion passes through the insulating elastic sheet in a thickness direction thereof.
Electronic components such as a resistor, a capacitor, an integrated circuit (IC), and a large-scale integrated circuit (LSI) are mounted on a printed circuit board using a reflow oven. This is a mounting method in which electronic components are arranged on a solder paste applied in a circuit pattern of the printed circuit board and the solder is melted in a reflow oven, so that the circuit pattern and the electronic components are electrically connected and fixed in place. There is known a connector sheet in which heat weldable powder that is heat weldable to a metal foil of a printed circuit board is formed in an exposed manner on at least one surface of an elastic sheet in order to mount the connector sheet together with other electronic components in a reflow oven (PTL 1).